金刚石砂轮和CBN砂轮修整廓形误差的理论和实验研究

用ＧＣ杯形砂轮修整金刚石砂轮和ＣＢＮ砂轮，是一种有效的修整方法，但这种修整方法的修整成形机理和被修整砂轮的廓形精度分析亟待解决。本文提出了新的基于微分学的修整分析模型，导出了不同修整参数下的修整廓形数学表达式，从而阐明了修整误差产生的原因，提出了修整误差定量计算分析的方法，并指导实验取得了在１７ｍｍ宽的砂轮廓形线上直线性误差仅为１ｕｍ的修整结果。     

Where to for Brazil's Cities? Citizen Empowerment or Global Marketing?

An awakening interest in public space in Brazilian cities is emphasising the value of existing civic areas. Guilherme Wisnik , a critic, curator and professor at the Faculty of Architecture and Urbanism of the University of São Paulo, looks at the history and potential future of Brazil's urban spaces. He highlights how despite the introduction of innovative Modernist design in the mid-20th century, which forged ‘a new relationship between architecture, urbanism and landscape design’, more recently the country's cities have been subject to the vicissitudes of market and political forces.     

2010年南非世界杯主办城市与赛场漫谈

4年一度的世界杯,总是能吸引全球人的目光。南非世界杯毫无疑问是2010年夏天的最大焦点,全世界的话题都集中在这项超级体育盛事上。本文主要介绍分析2010年南非世界杯的主办城市和主办赛场,并就世界杯赛场氛围及其文化延展进行探讨。     

第18届世界杯赛亚洲队与前8名队运用快速反击战术的比较分析

采用录像观察与统计分析的方法对第18届世界杯足球赛亚洲队与前8名运用快速反击战术的情况进行了比较分析.结果表明,亚洲队运用快速反击战术的能力与前8名相比存在着一定的差距,其主要原因在于运用快速反击的质量不高;东、西亚队在运用快速反击战术方面各具特点.     

Time domain modeling of cup anemometers using artificial neural networks

Under rapidly fluctuating wind speed, high inertia cup anemometers have a tendency to overspeed. The main objective of this article is to develop an inverse time domain model that could be used in real-time during cup anemometer operation to minimize the so-called “u-error”. A model proposed by Kristensen and an artificial neural network (ANN) direct model were first investigated to simulate the dynamic behavior of a heated cup anemometer with relatively high rotor inertia. Once the anemometer behavior was known, several virtual inputs were generated and the direct model was used to predict the instrument behavior. These models were built to emphasis the non-linear relationship between the free stream fluctuating wind and the wind speed measured by the anemometer. A semi-empirical inverse model derived from Kristensen's model was then studied and an ANN inverse model was suggested in order to minimize the so-called u-error. A methodology is proposed to gather the appropriate data to create both the direct and inverse model using an artificial neural network. The output of each model was compared with experimental data for validation and good agreement was found between the ANN models and the experimental data used for validation.     

新型轴承润滑脂助溶剂的研制

通过对五种不溶于锂基脂助溶剂的轴承润滑脂的助溶试验，选配出新助溶剂的配比，研制出新型助溶剂。     

Cold repeated forming of compact for aluminium foam

A cold repeated forming process of compacts for producing metal foams was developed in order to strongly bond powder particles. In this process, the compact undergoes severe plastic deformation for the strong bonding of particles by repeated backward extrusion and cup compression, and thus the compact largely foams owing to the accumulation of gas released from blowing agents inside the compact during heating. The cold repeated forming process without heating is much simpler than that for the conventional hot extrusion process. The relative density of the foam was decreased by adding silicon powder to the compact, and an aluminium foam having a relative density of 0.27 was obtained using two repeats of backward extrusion and cup compression, 1.5 mass% titanium hydride powder and 4 mass% silicon powder. In addition, a one-piece foam was successively produced from the bonding of two compacts during the foaming in a die. It was found that the cold repeated forming of compacts is effective for the production of metal foams.     

On cup anemometer performance at high altitude above ground

In this paper, an experimental wind tunnel test campaign to assess the possibility of using cup anemometers at high altitude (~20 km) is performed. The experimental procedure consists of measuring the evolution of the rotational frequency for different wind dynamic pressures for different cups and the center of rotation radius. With particular interest on the point at which the rotation stops for decreasing values of the dynamic pressure is considered as the limit value for the anemometer operation. The results show that large cup radius anemometer rotors present more stable behavior (its stopping point at low wind speeds being less affected by the cups’ center rotation radius). The authors conclude that cup anemometers can be used at high altitude above ground. Results show that an anemometer equipped with a 40 mm cup radius rotor could be considered operative up to an altitude of 25 km above ground.     

Square cup deep drawing and 2D-draw bending analysis of Hadfield steel

Hadfield steel is the dominant material in the production of bullet proof steel helmet for military uses. The conventional bullet proof steel helmets are extensively fabricated by cold forming (deep drawing) 1.2 mm Hadfield steel sheets at room temperature. This paper presents the experimental analysis of the square cup deep drawing and 2D-draw bending of Hadfield steel as a continuation of an international bench mark research program organized by NUMISHEET'93 organising committee in Japan. The draw-in values of the flange have been determined for various punch travels in the square cup operation. The principal strains were evaluated in three directions from grid measurments for those punch travels. Springback values and sidewall curls were also described in 2D-draw bending operation. The experimental results were compared with that of ones in mild steel.     

高炉耐火炉衬设计原则及“陶瓷杯”的应用

随着新型耐火材料的发展，“耐火材料法”在高炉内衬的设计中也得到了越来越广泛的应用，采用该法的主要好处是热损失小、炉缸状况稳定。以“耐火材料法“为基础，将导热性不同的材料进行合理安排后设计出了用于高炉炉缸的“陶瓷杯”。从１９８４年到１９９３年已有２３套“陶瓷杯”得到了安装或订购。